Twisting machine



May 16, 1933. M. H. DAMERELL 1,909,097

TWISTING MACHINE Original Filed Sept. 18, 19.30 4 Sheets-Sheet NJ JMW XWP M y 1933. M. H. DAMERELL 1,909,097

TWISTING MACHINE Original Filed Sept. 18, 1950 4 Sheets-Sheet 3 mhxkmerezfi y 16, 1933- M. H. DAMERELL 1,909,097

0riginal,File i Sept. 18, 1930 4 Sheets-Sheet 3 VWJY y 5 1933- M. H. DAMERELL 1,909,097

TWISTING MACHINE Original Filed Sept. 18, 1930 4 Sheets-Sheet 4 Patented May 16, 1933 UNITED STATES PATENT OFFICE COMPANY, OF WORCESTER, MASSACHUSETTS, A CORPORATION OF MASSACHUSETTS I rwrs'rme MACHINE Application filed September 13,.1930, Serial No. 482,844. Renewed October 8, 1932.

i This invention relates to a machine for twisting a two-bladed propeller or for perdefinitely related twisting operations may be effectively performed. 1

More specifically it-is the object of my invention to provide means by which the two blades of an airplane type propeller may be simultaneously twisted to a desired extent in opposite directions with respect to the stationary hub portion and in which the amount of twisting movement of the tips of the blades may be definitely restricted to a substantially less turning angle.

My invention further relates to arrangements and combinations of parts which will be hereinafter described and more particularly pointed out in the appended claims.

A preferred form of the invention is shown in the drawings, in which Fig. 1 is a partial front elevation, partly in section, of my improved twisting machine;

Fig. 2 is a plan view of the lower part of ilsjhe machine, taken along the line 22 in Figs. 3 and 4 are sectional end elevations, looking in the direction of the arrows 3 in Fig. 1 but showing the parts in different positions;

Figs. 5 to 9 inclusive are detail sectional end elevations, taken along the lines 55, 66, 77, 88 and 99 in Fig. 1 respectively;

Fig. 10 is a view similar to Fig. 5 but shelwmg the parts in a difl'erent position; an

Fig. 11 is a side elevation of a completed propeller.

Referring to the drawings, I have shown my improved twisting machine as comprising upper and lower middle. dies 10 and 11, upper and lower end dies 12 and 13, and upper and lower twisting dies 14 and 15. The lower middle die 11 and the lower end dies 13 are mounted on fixed supporting members 17 and 18 respectively.

The lower twisting dies 15 are mounted in movable trunnions or supports 20, mounted for angular movement in fixed base or frame members 21. The upper middle die 10 and the end dies 12 are fixed to depending members 24 and 25, which in turn are secured to a vertically movable head 26.

The upper twisting dies 14, are mounted in trunnions 30, which are angularly movable in depending supporting members 31, whichor projecting portions 33 to which the lower ends of actuating links 35 are pivoted at 36.

Links 40 (Figs. 3 and 4) are pivoted at one end to each upper trunnion member 30 and at the opposite end to levers 41 swinging on fixed pivots 42 and connected to one end of heavy coil springs 43. The springs 43 act to hold the trunnions 30 so that the upper dies 14 will be in the substantially horizontal position shown in Fig. 3 when the head 26 is raised. When the trunnions are moved angularly to twist the propeller blades, the links 40 and arms 41 assume the position shown in Fig. 4.

The head 26 is preferably raised and lowered by hydraulic mechanism (not shown) and the links 35 are also preferably actuated by hydraulic cylinders (not shown).

For a complete disclosure of hydraulic mechanism suitable for operating the head 26 and the links 35, reference is made to my prior Patent No. 1,274,390, issued August 6,

For present purposes, it may be stated that the upward and downward movements ofthe head 26 and the links 35 are poweractuated and manually controlled and that the head 26 may be moved downward to press the upper dies with very substantial pressure against the lower dies and against a propeller P resting thereon.

Attention is now called particularly to the movable dies 14 and 15. Fig. 5 shows the relation of these parts at the inner end, of the dies 14 and 15, adjacent to the hub portion 44 of the propeller P. On this section line 5-5 the dies 14 and 15 closely en gage the propeller P in its original position and. without substantial movement therefrom.

In Fig. 6 the original position of the propeller is indicated in dotted lines and the position of the propeller when the dies are closed but before angular movement thereof begins is indicated in full lines, from which it appears that the dies in closing twist each propeller blade on the section line 66 through a slight forward angle or in the direction. of subsequent twisting. This angle in the example illustrated is 218.

-Fig. 7 indicates that each propeller blade along the section line 77 is similarly twisted forward by the closing of the dies through a slight angle, indicated in the drawings as being 42.

Fig. 8 indicates that on the section line 8-8 the closing of the dies causes the pro- ;peller blades to be twisted backward or in an opposite direction to the subsequent twistin movement of the dle's' by an angle of 3 48 Flg. 9 shows a section through the end dies 12 and 13 and shows in full lines the position of the propeller when the dies close, which position is flat and without displacement in either direction. It will be noted, however that the dies 12 and 13 are cut away so that the'ends of the propeller blades have a limited free turning movement therein.

The hub 44 ofthe propeller fits snugly in the lower middle die 11 and is firmly retained therein by the upper middle die 10 when the dies are closed.

In the operation of the machine, a propeller P is placed in the lower dies, as indicated in Fig. 1, and the head 26 is then lowered, bringing the upper dies in firm engagement with the different portions of the propeller. This closing of the dies causes the various preliminary angular displacements above described.

A definite and predetermined turning or twisting movement of the trunnions 20 and 30 and the movable dies 14 and 15 then takes place, the parts moving from the position shown in Fig. 3 to that shown in Fig. 4. In the example shown in the drawin s, the trunnions and dies are each turned t rough an angle of 22 48 but it will be notedthat one set of trunnions turns clockwise and the other set anti-clockwise, as viewed from one end of the propeller.

The slight initial twisting movements caused by the closing of the dies as above described, are added to or subtracted from the turning movements of the dies and trunturning movement of the dies is additional to the initial twist or displacement and the Lfinal' twisted position of the propeller on these sections is at angles of 25 6 and 23 30 respectively, relative to the initial orv horizontal position of the blades. Along the section line 8-8 the initial displacement was in the backward direction and the turning of the dies through 22 48 produced a final twist of 19 in the blades at these points.

The tips of the blades, as previously stated, remain in initial position when engaged by the end dies, but are free to turn through a limited angle when the intermediate portions of the blades are twisted by the movable dies. This angle, as shown in Fig.

9, is 14 and the twisting movement of the ends or tips of the blades is thus limited to approximately two-tl1irds of the twisting movement applied to the intermediate portions or to a displacement of 14.

. The propeller P in its final or twisted form is clearly shown in Fig. 11.

The exact twisting movement of the movable dies may be predetermined by a suitable adjustable stop, such "as the screw 50 in Figs. 3 and 4. It will thus appear that by a peculiar and novel construction of the twisting dies and also of the fixed and dies, I am able by twisting movement of a single pair of dies for each blade to twist the blade at substantially varying angles on different sections and to confine the twist of the tips of the blades to a predetermined but substantial smaller angle.

This is accomplished by the coaction of the fixed hub-holding dies, the fixed end dies, which, however, permit a limited twisting movement of the tip of each blade, and the movable intermediate dies which produce varying twisting effects due to the initial action of the dies on the blade preliminary to the twisting movement of the dies.

Having thus described my invention and the advantages thereof, I do not wish to'be limited to the details herein disclosed, otherwise than as set forth in the claims, but what I claim is 1. A machine for twisting propeller blades comprising a pair of hub-holding dies rela tively movable to and from fixed clamping position, means to twist a propeller blade through a defined angle while held by said dies, and means to restrict the twistin moveing begins, whereby the final twisted angle is reduced on certain sections of the propeller blade.

3. A machine for twisting propeller blades comprising a pair of hub-holding dies relatively movable to and from fixed clamping position, a pair'of blade-twisting dies relatively movable to and from clamping position and also movable angularly while in clamping position, means to move said twisting dies angularly, means to limit said twisting movement, and a pair of tip-holding dies relatively movable to and from clamping position, said tip-holding dies engaging the tip portion of the propeller blade, and said tip portion having a limited free twisting movement in said holding dies.

4. A machine for twisting propeller blades comprising a pair of hub-holding dies relatively movable to and from fixed clamping position, a pair of blade-twisting dies relatively movable to and from clamping position and also movable angularly while-in clamping position, means to move said twisting dies angularly, means to limit said twisting movement, and a pair of tip-holding dies relatively movable to and from clamping position, said tip-holding dies engaging the tip portion of the propeller blade and havin a tip-holding recess permitting limited twlsting movement of said tip portion therein.

5. A machine for twisting ropeller blades comprising a pair of hub-h ding dies relatively movable to and from fixed clamping position, a pair of blade-twisting dies relatively movable to and from clamping position and also movable angularly while in clamping position, means to move said twisting dies angularly, means to limit said twisting movement, a pair of tip-holding dies relatively movable to and from clamping position, said tip-holding dies engaging the tip portion of the propeller blade, and said twisting dies beingefi'ective to distort the proatively movable to and from clamping position, said tip-holding dies engaging the tip portion of the propeller blade, and said twisting dies being effective to distort the propeller blade angularly from initial position by the closing of said dies thereon and such distortion being both forward and backward with respect to the direction of subsequent twisting of said blade.

7. A machine for twisting propeller blades comprising a pair of hub-holding dies relatively movable to and from fixed clamping position, a pair of blade-twisting dies relatively movable to and from clamping position arid also movable angularly while in clam ed position, means to move said twisting ies angularly, means to limit said twisting movement, a pair of tip-holding dies relatively movable to and from clamping position, said ti -holding dies engaging the tip portion of t e propeller blade, and said twisting dies being effective to. distort the propeller blade angularly from initial position by the closing of said dies thereon and such distortion being of diii'erent angular amounts at difierent transverse sections of said blade.

In testimony whereof I have hereunto affixed my signature.

MARK H. DAMERELL.

peller blade angularly from initial position I by the closing of said dies thereon.

6. A machine for twisting propeller blades comprising a pair of hub-holding dies relatively movable to. and from fixed clamping position, a air of blade-twisting dies relatively movable to and from clamping position and also movable angularly while in clamping position, means to move said twisting dies angularly, means to limit said twisting movement, a pair of tip-holding dies rel- 

